BTA HF Client should use dynamic control block

Most of the functions in bta_hf_client_at.cc are
currently using a static field for passing callbacks to
BTIF layer. In order to support multi device we need to make
the functions have a parameter which denotes the device.

In order to pass all the required information we choose to
pass the control block for the device instead.

Bug: b/30984220
Test: Manual regression test

Change-Id: Iac692d7e28df3955ddbd28707c323c41714bd86a